The former Manchester United forward suffered the injury during his side's 3-0 defeat at the hands of Real Madrid on Wednesday.
The full extent of the problem is not yet known, but the 24-year-old is likely to miss the majority of the season.
The Italian moved to the La Liga side in 2007.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Atletico MadridAtletico | 18 | 12 | 5 | 1 | 33 | 12 | 21 | 41 |
| 2 | Real Madrid | 18 | 12 | 4 | 2 | 41 | 18 | 23 | 40 |
| 3 | Barcelona | 19 | 12 | 2 | 5 | 51 | 22 | 29 | 38 |
| 4 | Athletic Bilbao | 19 | 10 | 6 | 3 | 29 | 17 | 12 | 36 |
| 5 | Villarreal | 18 | 8 | 6 | 4 | 34 | 30 | 4 | 30 |
| 6 | Mallorca | 19 | 9 | 3 | 7 | 19 | 21 | -2 | 30 |
| 7 | Real Sociedad | 18 | 7 | 4 | 7 | 16 | 13 | 3 | 25 |
| 8 | GironaGirona | 18 | 7 | 4 | 7 | 26 | 25 | 1 | 25 |
| 9 | Real BetisBetis | 18 | 6 | 7 | 5 | 21 | 22 | -1 | 25 |
| 10 | Osasuna | 18 | 6 | 7 | 5 | 23 | 27 | -4 | 25 |
| 11 | Celta Vigo | 18 | 7 | 3 | 8 | 27 | 28 | -1 | 24 |
| 12 | Rayo Vallecano | 18 | 5 | 7 | 6 | 20 | 21 | -1 | 22 |
| 13 | Las PalmasLas Palmas | 18 | 6 | 4 | 8 | 23 | 27 | -4 | 22 |
| 14 | Sevilla | 18 | 6 | 4 | 8 | 20 | 27 | -7 | 22 |
| 15 | Leganes | 18 | 4 | 6 | 8 | 17 | 28 | -11 | 18 |
| 16 | AlavesAlaves | 18 | 4 | 5 | 9 | 21 | 30 | -9 | 17 |
| 17 | Getafe | 18 | 3 | 7 | 8 | 11 | 15 | -4 | 16 |
| 18 | Espanyol | 18 | 4 | 3 | 11 | 16 | 30 | -14 | 15 |
| 19 | Valencia | 17 | 2 | 6 | 9 | 16 | 26 | -10 | 12 |
| 20 | Real ValladolidValladolid | 18 | 3 | 3 | 12 | 12 | 37 | -25 | 12 |
| > La Liga Full Table | |||||||||
